var isMinNS4 = (navigator.appName.indexOf("Netscape") >= 0 &&
                parseFloat(navigator.appVersion) >= 4) ? 1 : 0;
var isMinIE4 = (document.all) ? 1 : 0;
var isMinIE5 = (isMinIE4 && navigator.appVersion.indexOf("5.") >= 0) ? 1 : 0;

//-----------------------------------------------------------------------------
// Image utilities.
//-----------------------------------------------------------------------------

function getImage(name) {

  if (isMinNS4) {
    return findImage(name, document);
  }
  if (isMinIE4)
    return eval('document.all.' + name);
  return null;
}

function findImage(name, doc) {

  var i, img;

  for (i = 0; i < doc.images.length; i++)
    if (doc.images[i].name == name)
      return doc.images[i];
  for (i = 0; i < doc.layers.length; i++)
    if ((img = findImage(name, doc.layers[i].document)) != null) {
      img.container = doc.layers[i];
      return img;
    }
  return null;
}

function getImagePageLeft(img) {

  var x, obj;

  if (isMinNS4) {
    if (img.container != null)
      return img.container.pageX + img.x;
    else
      return img.x;
  }
  if (isMinIE4) {
    x = 0;
    obj = img;
    while (obj.offsetParent != null) {
      x += obj.offsetLeft;
      obj = obj.offsetParent;
    }
    x += obj.offsetLeft;
    return x;
  }
  return -1;
}

function getImagePageTop(img) {

  var y, obj;

  if (isMinNS4) {
    if (img.container != null)
      return img.container.pageY + img.y;
    else
      return img.y;
  }
  if (isMinIE4) {
    y = 0;
    obj = img;
    while (obj.offsetParent != null) {
      y += obj.offsetTop;
      obj = obj.offsetParent;
    }
    y += obj.offsetTop;
    return y;
  }
  return -1;
}

function moveLayerTo(layer, x, y) {
  if (isMinNS4)
    layer.moveTo(x, y);
  if (isMinIE4) {
    layer.style.left = x;
    layer.style.top  = y;
  }
}

function findLayer(name, doc) {

  var i, layer;

  for (i = 0; i < doc.layers.length; i++) {
    layer = doc.layers[i];
    if (layer.name == name)
      return layer;
    if (layer.document.layers.length > 0)
      if ((layer = findLayer(name, layer.document)) != null)
        return layer;
  }
  return null;
}

function getLayer(name) {

  if (isMinNS4)
    return findLayer(name, document);
  if (isMinIE4)
    return eval('document.all.' + name);
  return null;
}